This invention relates to a method, an arrangement and a power supply for a process of electrochemically machining an electrically conductive workpiece by applying electrical machining pulses between the workpiece and an electrically conductive electrode while electrolyte is supplied between the workpiece and the electrode.
Electrochemical machining is a process in which an electrically conductive workpiece is dissolved at the location of an electrode while electrolyte and electric current is supplied. For this purpose, the electrode is brought into the proximity of the workpiece and, while electrolyte is fed into the gap between the workpiece and the electrode a powerful current is passed through the workpiece and the electrode via the electrolyte, the workpiece being positive with respect to the electrode. The current is applied in the form of machining pulses having a given amplitude and duration. In the intervals between the machining pulses the electrolyte is renewed. During the application of the machining pulses the electrode and the workpiece are moved towards one another with a given feed rate, as a result of which the electrode forms a cavity or eventually a hole in the surface of the workpiece, the shape of this cavity or hole corresponding to the shape of the electrode. This process can be used, for example, for making intricate cavities or holes in or for shaping hard metals or alloys.
The copying precision with which the shape of the cavity or the hole in the workpiece follows the shape of the electrode is important for the quality of the result. Meanwhile, many publications in the form of articles in periodicals and patent documents have appeared in which proposals have been made to improve the copying precision of electrochemical machining.